Jacek Stecki - Academia.edu (original) (raw)
Papers by Jacek Stecki
The paper is concerned with experimental verification of a Dynamic Contamination Control (DCC) mo... more The paper is concerned with experimental verification of a Dynamic Contamination Control (DCC) model, which is used to model and simulate dynamic changes in contamination levels in hydraulic systems. The DCC modeling approach was developed at Monash University and has not been previously verified by experiments on multi-branch hydraulic systems. To verify the DCC modelling approach a test rig simulating a multi-branch hydraulic system was designed and built to allow investigation of the distributions of particulate contamination within the circuit. To accelerate the tests, ingression of contaminants at different locations in the circuit and generation of wear particles by system components were simulated by injecting known quantities of contaminants at various circuit locations. The experiments, covering various combinations of flow rates, indicated a good agreement with the simulated results obtained with the DCC model and thus confirmed the reliability of the DCC model in assessment of contamination levels in hydraulic systems. The paper describes the experimental set-up, the results of the experiments and comparison between results of experiments and simulations carried out with the DCC model.
PHM Society European Conference, Jul 2, 2018
Developing PHM capability for a system is a multi-staged process. This paper explores genetic alg... more Developing PHM capability for a system is a multi-staged process. This paper explores genetic algorithms, neural networks, fuzzy logic systems, AHP (Analytical Hierarchy Process), and Boolean logic to synthesize and fuse complex decisions arising in PHM design. Tools for PHM analysis are typically introduced and utilized towards the end of a products design or potentially after design. The methods proposed are tools that can be implemented during conceptual and early stage preliminary design prior to specific hardware design decisions being made. As a result, diagnostic capability can be developed along with the broader system allowing better embedded design of diagnostic instruments into the system and giving PHM a greater role in operation rather than being a secondary consideration of system development. Paddy Conroy et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 3.0 United States License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Industrial and Engineering Applications of Artificial Intelligence and Expert Systems, Jun 1, 1993
SAE Technical Paper Series, Sep 1, 1984
SAE technical paper series, Feb 1, 1992
Lubrication Engineering, 1985
SAE technical paper series, Feb 1, 1992
SAE technical paper series, Sep 11, 2000
IFAC Proceedings Volumes, Jul 1, 1993
the paper deserines a strategy for on-line automatic control of the contamination level of the wo... more the paper deserines a strategy for on-line automatic control of the contamination level of the working fluid in the hydraulic control and the luorication systems of modem heavy machinery. The strategy integrates condition monitoring of the fluid, inlelligent interpretation and use of the results and the way they are changing, and selective action to correct deficiencies. Because of the ubiquitous and heuristic nature of fluid contamination, a knowledge-based approach involving fuzzy logic is taken for the analysis and decision-making component of the strategy. The work is well advanced, though not complete.
Tribology transactions, 1988
This paper presents the results of tests on heavily loaded self-aligning bearings carried out to ... more This paper presents the results of tests on heavily loaded self-aligning bearings carried out to assess the effect of molybdenum disulphide (MoS2) on bearing life. Two populations of bearings were tested each comprising more than 60 bearings. The same lubricating oil was used in tests of each population, but in the case of one population 1 percent of ultrapure MoS2 colloid was added to the oil. Under test conditions the test set of bearings lubricated by oil with MoS2 additive lasted longer than the control set of bearings lubricated by plain oil, with the confidence level of 98 percent supporting the results. The life of the test set of bearings was 60 percent greater than the control set of bearings, and the spread in distribution of bearing lives, was less than those in the control set. Presented at the 42nd Annual Meeting in Anaheim, California May 11–14, 1987
In hydraulic winch systems control of gravity load during lowering is achieved by incorporating c... more In hydraulic winch systems control of gravity load during lowering is achieved by incorporating counterbalance valves. The amount of opening of a conventional counterbalance valve is controlled by pressure in the supply line, thus when the load is trying to run-away it will cause pressure decrease in the motor supply line and this will reduce the amount of opening of the counterbalance valve and stop uncontrolled descent of the load. Similarly, in the event of line failure the loss of pressure in the supply line will block the uncontrolled descent of the load. As the flow through the counterbalance valve is also dependent on the pressure drop across the valve, the speed of load descent for a given opening of the valve will also depend on the load changes. Stability of the load motion is an important consideration as unstable operation of the counterbalance valve may cause load oscillations and thus affect the safety of the winch. The paper presents stability analysis of a winch system which incorporates a novel, load compensated, counterbalance valve and provides recommendation for enhancing stability of winch systems.
The aim of the study was to investigate the dynamic behaviour of a wheel car system under various... more The aim of the study was to investigate the dynamic behaviour of a wheel car system under various braking and road surface conditions. An experimental "quarter car" rig was used to provide data for a computer simulation programme and also to verify experimentally computer predicted wheel car behaviour. Difficulty in direct measurement of wheel car velocities and accelerations lead to development of highly accurate indirect numerical methods. The pulse signals from photoelectric sensors were collected and then processed to provide data on wheel car velocities accelerations, friction and relative slip between wheel and the road surface. Additional data on pedal pressure, wheel loading etc, were also collected. The wheel car simulation programme using csmp was run on burroughs 6700 computer. Some experimental and simulation results are given.
SAE Technical Paper Series, 1985
Choix d'un fluide hydraulique difficilement inflammable. Criteres lies aux composants et au s... more Choix d'un fluide hydraulique difficilement inflammable. Criteres lies aux composants et au systeme
SAE Technical Paper Series, 1992
The paper is concerned with experimental verification of a Dynamic Contamination Control (DCC) mo... more The paper is concerned with experimental verification of a Dynamic Contamination Control (DCC) model, which is used to model and simulate dynamic changes in contamination levels in hydraulic systems. The DCC modeling approach was developed at Monash University and has not been previously verified by experiments on multi-branch hydraulic systems. To verify the DCC modelling approach a test rig simulating a multi-branch hydraulic system was designed and built to allow investigation of the distributions of particulate contamination within the circuit. To accelerate the tests, ingression of contaminants at different locations in the circuit and generation of wear particles by system components were simulated by injecting known quantities of contaminants at various circuit locations. The experiments, covering various combinations of flow rates, indicated a good agreement with the simulated results obtained with the DCC model and thus confirmed the reliability of the DCC model in assessment of contamination levels in hydraulic systems. The paper describes the experimental set-up, the results of the experiments and comparison between results of experiments and simulations carried out with the DCC model.
PHM Society European Conference, Jul 2, 2018
Developing PHM capability for a system is a multi-staged process. This paper explores genetic alg... more Developing PHM capability for a system is a multi-staged process. This paper explores genetic algorithms, neural networks, fuzzy logic systems, AHP (Analytical Hierarchy Process), and Boolean logic to synthesize and fuse complex decisions arising in PHM design. Tools for PHM analysis are typically introduced and utilized towards the end of a products design or potentially after design. The methods proposed are tools that can be implemented during conceptual and early stage preliminary design prior to specific hardware design decisions being made. As a result, diagnostic capability can be developed along with the broader system allowing better embedded design of diagnostic instruments into the system and giving PHM a greater role in operation rather than being a secondary consideration of system development. Paddy Conroy et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 3.0 United States License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Industrial and Engineering Applications of Artificial Intelligence and Expert Systems, Jun 1, 1993
SAE Technical Paper Series, Sep 1, 1984
SAE technical paper series, Feb 1, 1992
Lubrication Engineering, 1985
SAE technical paper series, Feb 1, 1992
SAE technical paper series, Sep 11, 2000
IFAC Proceedings Volumes, Jul 1, 1993
the paper deserines a strategy for on-line automatic control of the contamination level of the wo... more the paper deserines a strategy for on-line automatic control of the contamination level of the working fluid in the hydraulic control and the luorication systems of modem heavy machinery. The strategy integrates condition monitoring of the fluid, inlelligent interpretation and use of the results and the way they are changing, and selective action to correct deficiencies. Because of the ubiquitous and heuristic nature of fluid contamination, a knowledge-based approach involving fuzzy logic is taken for the analysis and decision-making component of the strategy. The work is well advanced, though not complete.
Tribology transactions, 1988
This paper presents the results of tests on heavily loaded self-aligning bearings carried out to ... more This paper presents the results of tests on heavily loaded self-aligning bearings carried out to assess the effect of molybdenum disulphide (MoS2) on bearing life. Two populations of bearings were tested each comprising more than 60 bearings. The same lubricating oil was used in tests of each population, but in the case of one population 1 percent of ultrapure MoS2 colloid was added to the oil. Under test conditions the test set of bearings lubricated by oil with MoS2 additive lasted longer than the control set of bearings lubricated by plain oil, with the confidence level of 98 percent supporting the results. The life of the test set of bearings was 60 percent greater than the control set of bearings, and the spread in distribution of bearing lives, was less than those in the control set. Presented at the 42nd Annual Meeting in Anaheim, California May 11–14, 1987
In hydraulic winch systems control of gravity load during lowering is achieved by incorporating c... more In hydraulic winch systems control of gravity load during lowering is achieved by incorporating counterbalance valves. The amount of opening of a conventional counterbalance valve is controlled by pressure in the supply line, thus when the load is trying to run-away it will cause pressure decrease in the motor supply line and this will reduce the amount of opening of the counterbalance valve and stop uncontrolled descent of the load. Similarly, in the event of line failure the loss of pressure in the supply line will block the uncontrolled descent of the load. As the flow through the counterbalance valve is also dependent on the pressure drop across the valve, the speed of load descent for a given opening of the valve will also depend on the load changes. Stability of the load motion is an important consideration as unstable operation of the counterbalance valve may cause load oscillations and thus affect the safety of the winch. The paper presents stability analysis of a winch system which incorporates a novel, load compensated, counterbalance valve and provides recommendation for enhancing stability of winch systems.
The aim of the study was to investigate the dynamic behaviour of a wheel car system under various... more The aim of the study was to investigate the dynamic behaviour of a wheel car system under various braking and road surface conditions. An experimental "quarter car" rig was used to provide data for a computer simulation programme and also to verify experimentally computer predicted wheel car behaviour. Difficulty in direct measurement of wheel car velocities and accelerations lead to development of highly accurate indirect numerical methods. The pulse signals from photoelectric sensors were collected and then processed to provide data on wheel car velocities accelerations, friction and relative slip between wheel and the road surface. Additional data on pedal pressure, wheel loading etc, were also collected. The wheel car simulation programme using csmp was run on burroughs 6700 computer. Some experimental and simulation results are given.
SAE Technical Paper Series, 1985
Choix d'un fluide hydraulique difficilement inflammable. Criteres lies aux composants et au s... more Choix d'un fluide hydraulique difficilement inflammable. Criteres lies aux composants et au systeme
SAE Technical Paper Series, 1992